Question

If tan A + sec A= ^, then the cos A =?


Please explain !!​

Answer 1

Answer:

tan θ + sec θ = ex….(i)

We know that,

sec2θ – tan2θ = 1

(sec θ – tan θ)(sec θ + tan θ) = 1

(sec θ – tan θ) ex = 1

sec θ – tan θ = 1/ex = e-x….(ii)

Adding (i) and (ii),

tan θ + sec θ + sec θ – tan θ = ex + e-x

2 sec θ = ex + e-x

2(1/cos θ) = ex + e-x

Therefore, cos θ = 2/(ex + e-x)